Flow-meter-indicator/recorder

Prototype for digitizing mechanical indicators and recorders used in propeller flowmeters.

Main Parts:

• Tiva C (TM4C123GH6PM) Microcontroller evaluation board
• Omron E6B2-CWZ6C Rotary Encoder (Incremental)
• LM2596 Switching Regulator

ToDo List:

General:

• LCD 16x2 (HD44780) customized driver
• QEI configuration and interrupt handling (direction change, index detection and timer expiration)
• Brown-out detection to improve reliability
• Watchdog module configuration to improve reliability
• LM2596 step-down(buck) converter desing to supply power from Battery/Alternator (Irrigation water pump) to the system.
• Mechanical coupling between Encoder and Propeller mechanism.
• Diode ORing circuit for power backup (SuperCapacitor).
• Timer modules configuration for timing managment (EEPROM Storage and others)

Flow Rate:

• Averaged encoder RPMs measurement
• Detection of the direction of rotation to avoid "Negative flow" measurement
• Regression between RPMs and Flow Rate from a reference flow meter (Calibration)
• Definition of upper and lower flow rate limits to avoid inaccurate measurements.

Total volume:

• Measuring the number of encoder turns
• Detection of the direction of rotation to avoid "Negative volume" measurement
• Regression between number of turns and Total volume from a reference flow meter (Calibration)
• Implementation of the EEPROM module for "Total volume" storage with wear leveling algorithm
• Interrupt handling for EEPROM storage in Brown-out conditions (Operating with SuperCapacitor)

Low Power (Further Design):

• Use of PIOSC as low power clock source
• Use of control pins for Enabling/disabling LCD and Encoder power input
• Hibernation state in absence of flow
• RTC Configuration for timing managment (EEPROM Storage, Trigger hibernation and restarts, etc)